The invention relates to a method for placing electronic components, in particular SMD components, on circuit carriers arranged in a placement unit, within the placement-related data being stored in a control computer unit which controls the placement units. Furthermore, the invention relates to a system for placing electronic components on circuit carriers arranged in a placement unit, having a control computer unit for controlling the placement units.
It is known, for populating circuit carriers, to provide a placement unit which automatically positions and contact-connects a plurality of electronic components, fed to said placement unit, according to a predetermined specification on the circuit carrier. The electronic components, which are maintained in the form of an array, are usually fed continuously to the placement unit. A control computer unit is provided for controlling the placement unit, which supplies placement-related data and by means of which the placement operation can be performed automatically.
The placement unit has a plurality of feed tracks to each of which a predetermined array is assigned. The array is assigned to the respective feed tracks manually during the equipment operation, with an operator reading a feed table. The erroneous assignment of an array to a feed track can occur on account of inattentiveness of the operator.
It is an object of the present invention to provide a method and a system for populating circuit carriers arranged in a placement unit which ensure secure and reliable assignment of the array to a predetermined feed track of the placement unit.
In order to achieve this object, equipment-related data are extracted from the placement-related data and transmitted to a portable equipment supervisory carrier which is coupled to a feed supervisory unit assigned to the placement unit. The electronic components are fed to the placement unit only when they are assigned to a feed track of the placement unit, the feed track being identified by the equipment-related data. A feed supervisory unit is provided in each case in the region of the feed to the placement unit. The supervisory unit has a control unit and a plurality of readers for reading component-related data stored on an identification carrier, and for reading equipment-related data stored on a portable equipment supervisory carrier. Means are provided such that equipment-related data can be derived from placement-related data present in electronic form in the control computer unit, which equipment-related data are written to the equipment supervisory carrier.
A particular advantage of the method according to the present invention is that supervisory data can be generated in a simple manner by the extraction of equipment-related data from the placement-related data present. The supervisory data can be used to check reliably and securely the assignment of arrays that are to be assigned to the respective feed tracks of the placement unit during an equipment operation. The equipment-related data are present in electronic form in a feed supervisory unit in which correct assignment of the array to the feed tracks is checked.
According to one preferred embodiment of the method according to the present invention, an enable signal is generated in the feed supervisory unit when the array is correctly assigned to the feed tracks. Placement can be effected only after the enable signal has been output. Consequently, the placement operation can be activated only after the checking of all arrays assigned to a placement unit. Erroneous population of the circuit carrier can thus be reliably avoided.
According to a further embodiment of the invention, the enable signal is generated only when there is an electrical connection between an equipment supervisory carrier, which characterizes a specific assignment of arrays, and the feed supervisory unit. The equipment-related data are advantageously stored exclusively on the equipment supervisory carrier, so that the current equipment-related data can be exclusively used for the supervision of the assignment. This eliminates the situation where incorrect equipment-related data used from previous equipment operations are used.
The system according to the present invention ensures the secure and reliable checking of the assignment of the array to predetermined feed tracks of the placement unit. Thus, the basic concept of the invention is to store the component-related data which characterize the array in an identification carrier, preferably connected to the array, and the equipment-related data which identify the predetermined assignment of the array to the feed tracks of the placement unit in an equipment supervisory carrier. By comparing the equipment-related data and the component-related data in a feed supervisory unit, the assignment can be checked electronically in a simple manner and, if appropriate, correction of the assignment can be signaled. The equipment-related data can advantageously be derived from the placement-related data available to a control computer unit. The access supervisory unit, which is preferably arranged in direct proximity to the placement unit, can be operated automatically and independently of the control computer unit.
By virtue of the fact that the equipment supervisory carrier is designed to be portable, the equipment-related data, once stored, can be fed to the access supervisory unit in a manner that allows them to be handled simply. The system is thus capable of being flexibly configured. There is no need for a data connection between the control computer unit and the access supervisory unit.
According to a further preferred embodiment of the system according to the present invention, the control computer unit is directly connected to a read/write device, so that after the equipment-related data have been generated, they can be stored directly on the portable equipment supervisory carrier. This enables fast and simple provision of the equipment-related data on the equipment supervisory carrier.
According to another preferred embodiment, the control computer unit is connected via a data line to a separate computer unit to which the equipment-related data are transmitted. This computer unit may be a commercially available personal computer equipped with a read/write device. This makes it possible to utilize an existing data network in order to write the equipment-related data to the equipment supervisory carrier at any desired location.
According to yet another embodiment of the present invention, a component computer unit may be provided which has a component database. This makes it possible not only for the actual component identifier of the electronic components arranged on the respective array to be stored electronically on the identification carrier, but for further information which characterizes the components to be additionally stored on the identification carrier. Consequently, the identification carrier contains component-related data which enable an operator at any timexe2x80x94by means of a portable readerxe2x80x94to identify the components combined on the array.
In another embodiment of the invention, the identification carrier and/or the equipment supervisory carrier are designed as a smart card, which have an electronic memory. In an advantageous manner, the corresponding data can be simply written or read from commercially available read/write devices.